This paper is concerned with an operational assistance system to a load transfer machine in a plane such as a manually guided vehicle and a crane without vertical transfer. In the transfer machine, collisions with obstacles are often occurred by the incorrect operations. Therefore, in order to avoid the obstacles to the transfer machine, the operational assistance system using 3-DOF(3 Degree of Freedom) joystick with reaction force display is proposed in this study. The 3-DOF joystick enables operator to manipulate the transfer machine with back-and-forth, left-and-right, and rotation motions. And, it has motors for presenting the reaction force on each axis. In this system, the joystick displays the reaction force which consists of the virtual elastic force and viscosity resistance, which are controlled by PD control gains. By associating the gains in the PD control with the distance between the obstacles and the transfer object, the joystick operation is constrained for avoiding the obstacles. The effectiveness of the proposed operational assistance system is verified by the experiments using the simulator of the transfer machine manipulated by the 3-DOF joystick.

This paper is concerned with an advanced attitude control of the vehicle body in the parallel two-wheel vehicle with underslung vehicle body. Since the parallel two-wheel vehicle has large wheels with its diameter of 1.05m, and the battery, the actuators and the controller are placed on the lower position in the vehicle body, the gravity center of the vehicle body with a passenger can be assigned at the lower position than the wheel axis. Therefore, the vehicle has a pendular structure that enables the vehicle body with the passenger to always maintain the stable posture, even if the vehicle is in the power-off or control-off condition. In order to suppress the sway of the vehicle body on the pitch axis while driving the vehicle, the attitude control system using an active mass system is constructed into the vehicle body. However, the behavior of the vehicle body with the passenger differs depending on person. In this study, a design method for the attitude control system with applicability to various passengers is proposed. The behavior of the vehicle body is related strongly with the passenger's properties. And, the control system using the active mass system is designed by a Backstepping Method. The robust control parameters for suppressing the behavior of the vehicle body associated with the passenger's properties is clarified in this study. The effectiveness of the proposed attitude control system with the active mass system is verified by the experiments using the parallel two-wheel vehicle with underslung vehicle body.

Today, Virtual Reality (VR) technology has been widely applied in various fields. In past research, the influence of inducing VR in humans through the human senses or virtual effects has been studied. However the methods used to analyze human sensation have only involved measuring the center of gravity and questionnaire surveys. On the other hand, it is known that the sensation induced by VR affects the userfs behavior with specific frequency component. If this kind of behavior can be modeled by using simple model parameters, it has possibility to control the humanfs behavior using visual stimulation or to increase their reality. And its application field has widely for the VR application with higher reality or medical rehabilitation supports and so on. In this papar, the human behavior model using first order system with parameters has been proposed. And identification method for their parameters by using frequency analysis of human behavior with measurement system is also proposed. In addition, various experiments are performed using the proposed system in order to evaluate its effectiveness. As a result, validity of proposed model and its parameters are confirmed through the analysis of experimental results.

Holonomic omnidirectional mobile robots are useful because of their high level of mobility in narrow or crowded areas, and omnidirectional robots equipped with normal tires are desired for their ability to surmount difference in level as well as their vibration suppression and ride comfort. A caster-drive mechanism using normal tires has been developed to realize a holonomic omnidiredctional robot, but some problems has remain. Here we describe effective systems to control the caster-drive wheels of an omnidirectional mobile robot. We propose a Differential-Drive Steering System (DDSS) using differential gearing to improve the operation ratio of motors. The DDSS generates driving and steering torque effectively from two motors. Simulation and experimental results show that the proposed system is effective for holonomic omnidirectional mobile robots.